In primary spontaneous pneumothorax (PSP) requiring intervention, removal of air from the pleural space can be achieved by manual needle aspiration or by pleural drainage after insertion of a chest tube. This study aimed to evaluate the efficacy and safety of a serial-steps approach with a single system (small-calibre catheter/Heimlich valve) in a homogeneous population of patients with a first episode of PSP. All patients had an 8.5 F distally multiperforated polyurethane pigtail catheter inserted via the anterior route, at the bedside without any guidance, using the Seldinger technique. A one-way Heimlich valve was connected to the catheter, allowing the air to flow spontaneously outwards for 24-48 h. Thereafter, if the lung failed to re-expand wall suction was applied. Patients with an air leak persisting for >4 days were referred for surgery. Primary end-points were success rates at 24 h and 1 week, and 1 yr recurrence-free survival. In total, 41 consecutive patients entered the study. They were typically thin, young, smoking males. No procedure-related complications were observed. The need for pain relief medication was minimal. Within the first 24 h, most of the patients were able to walk around and half of them were able to take a shower with their catheter in place. The 24-h and 1-week success rates were 61 and 85%, respectively, and the actuarial 1-yr recurrence rate was 24%. Four patients underwent surgical pleurodesis because of a persistent air leak. The length of stay when excluding the four surgical cases was 2.3+/-1.3 days. When 24-h and 1-week success rates and recurrence at 12 months were taken as end-points, the method described here is as effective as simple manual needle aspiration or a conventional chest tube thoracotomy. These results support further studies assessing this "one system, serial-steps approach" in an outpatient management algorithm.